This multi-country study aims to track and analyse online conversations related to immunisation on social media and mainstream media in India, Kenya, Nigeria and Pakistan. Findings from the study showed that in social media, Nigerian and Pakistani politicians are active and influential in the vaccination debate and the political dimension is often referred to when discussing the failure to eradicate diseases such as polio. However, in Kenya, religious and ideological aspects were more frequently discussed. Twitter activity is primarily driven by sharing of news stories in all countries whereas Facebook focuses on the 'distrust' and 'ideals' categorisation. Finally it was found that mainstream media related different actors and entities than social media. The project shows how methods including sentiment analysis, topic classification and network analysis can be used to support public health workers and communication campaigns.